This seems to have a regional type of success and it appears more successful in springtime. I kept track of my results very deliberately for two years including two spring seasons in ALaska, and Idaho and two long fall seasons in Washington, Idaho and Montana. I did this to build some data for the magazine I write for( Bear hunting magazine).
Without posting tons of numbers let me just post a few details that should shed some light on this for you. All these instances were noted and documented by first having seen the bear and then watching the reaction. In the high alpine of the mountians we could easily see bears to watch the reaction. In Alaska we could find bears walking salmon streams and beach combing to watch their reactions as well.
About 25% of the time when a bear heard a very loud predator call they would run the opposite direction. About 25% of the time when the call was low or at least not blasting loud the bear would look the direction of the call for a moment and either keep doing what ever he was or leave the opposite direction. From this it seems at least half the bears hearing a predator call have no desire to become predatory or fight another animal over it's food.
About 25% of the time regardless of the type of call the bears would wander about the area completely ignoring the sound just doing what ever it was they were doing previousley.
About 15% of the time they would make a half hearted effort to get a better look at the location of the sound, not for interest of eating the source but just out of curiosoty. Some walked much closer but none made a serios effort to "get the call"
About 5% of the time the bears would go to the highest point near to them and stand looking at the sound. These did not come any closer they just stood and watched for about as long as the sound was going. Many after looking for a few minutes would drop down and slowly wander away.
Finally the remainig two full percent would actually have a desire to get the source of the sound. This happend only 3 times in over 100 bears noted in the test. All three were clearly males and one was shot. All three were large mature adults. The majority of Females bolted at the first sound of a predator call.
Because of this low frequency of bear response I have reasoned that it's a poor choice of hunting for bears in an area where you cannot see them first to call them closer. "cold calling" has very low success in the states I have tried it. All three bears were called in springtime and I associate this with the normal births of big game during that time. We tried many different calls on these bears many on the same bears during a single visual event. We used kid goat cry's, lamb distress, fawn distress, and both rabbit and jack rabbit calls. With both hand and wireless remote electronic calls. I even used a bear cub bawling tape to see the reacion.
I'm sure there are other ares like Nova Scotia where the black bear population is primarily a predator through evolution, or where significant winter kills of big game occur. However in Western Montana, all of Idaho, Washington and coastal Alaska the results were not promising.
I will continue to search for visual contact of a bear before I try to call one by setting up a cold call. The results were far to weak to waste my time with. When you can see one first and you cannot get closer it's worth the chance to bring him closer. I know also that they are very easily spooked with high volume, our best success was to have them hunt the low or weak sounding animal.
Good luck and I hope this little bit of input helps you.
